SU1109189A1 - Catalyst for dehydrogenizing ethanol - Google Patents

Description

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The invention relates to catalysts for the dehydrogenation of alcohols. in particular ethanol.

A known catalyst for dehydration of primary alcohols, containing 5% metallic copper, on a modified alkali metal hydroxide, gumbrin Cl.

However, this catalyst has a selectivity of 97.5% at a conversion of 92%.

Also known is a catalyst for dehydrogenating ethanol containing 1-5% chromium oxide and 95-99% copper 2.

The disadvantages of the catalyst are low productivity of 8, 4-17.2 g / l of catalyst per hour and a short period (not more than 250 hours) of its active work.

Closest to the present invention, there is a catalyst for dehydrogenating ethanol containing 14-21% chromium oxide and 79, -86% copper oxide SPZ.

However, the known catalyst is not sufficiently high acetaldehyde selectivity - 93-98.0%.

The purpose of the invention is to increase the selectivity of the catalyst.

This goal is achieved by the fact that the catalyst for ethanol dehydrogenation, containing copper-containing component, and chromium oxide, as the copper-containing component contains copper and, additionally, silicon carbide, chromium and silicon with the following content of components, wt.%:

Copper0,3-0,5

Chromium oxide 0,24-0,3

Silicon Carbide 70-98,6

Chrome 0.5-1.0

Silicon Rest

The catalyst is prepared as follows.

A mixture of bakelite in alcohol is added to a mixture of powders containing silicon carbide grade K4-55, silicon grade KRO, metallic chromium, petroleum coke for binding, and the mixture is thoroughly mixed. The mixture is then pressed into tubes in the form of a mouthpiece or hydrodynamic pressing at a specific pressure of 45 tons / cm.

After that, the half-finished product is kept in an oven at 150 ° C for 3 hours, sintering in argon is performed for 2.5 hours with step heating and is kept

0r

1 H at 950 C-, impregnated with solutions of copper nitrate and chromium acetate with a total concentration of 0.6-1.0 wt. with a weight ratio of 1.25: 1. Then, the obtained products are dried at 120 ° C for 2 hours in a drying cabinet, calcined in a muffle furnace at 400-600 ° C for 3 hours, and reduced in a stream of hydrogen for 30-60 minutes.

The catalyst obtained is tested in the dehydrogenation of ethyl alcohol at 300-400 ° C and a space velocity of 2.9-5.7 h.

The proposed catalyst. Showed with: 100% efficiency, i.e. no by-product, ethyl acetate is formed.

Example 1. To a mixture of powders containing, g: K-4-55 140 silicon carbide, metallic chromium 2, silicon 56.92, petroleum coke 1.5. for a bond, which will later burn out, add a solution of bakelite in alcohol 100 ml, mix the mixture thoroughly. Then the mixture is pressed in the form of tubes by the method of mouthplate; spring at a specific pressure of 4. After that, the resulting product is dried in a drying oven for 3 hours and sintering in argon at 1850 ° C for 2.5 hours with heating by heating and holding for 1 hour at 950 ° C. The cooled product is impregnated with a mixture of aqueous solutions of copper and chromium salts, taken in the following ratios: 2.79 rCu (NOj) 2 6H20, dissolved V294 g of water, and O, 78, g of Cr (C2 HcSy HjO, dissolved in 130 g of water for 40 minutes Then the obtained product is dried at 120 ° C for 2 hours in a drying cabinet, calcined in a muffle furnace for 3 hours and reduced in a stream of hydrogen for 30 minutes.

The catalyst thus obtained has the composition in wt.%:

Copper0,3

Chromium oxide 0,24

Silicon Carbide 70.0

Chrome .. 1.0

Silicon Rest

Ethyl spirTv Amount of 100 m is passed through a poly5T1enny catalyst with a bulk velocity of 2.9. The catalyst is heated by applying a voltage of 6.4 V to it, which provides the temperature in the reaction zone of 200 ° C. The yield of acetaldehyde is 30%, the selectivity is 100%. Example 2: A mixture of powders containing, g: K-4-55 177.2 silicon carbide, chromium 1.0, silicon 20.46,;, petroleum coke for the bond, 1.5, g. add a solution of bakelite in alcohol in an amount of 100 ml, which also further burn out, and mix the mixture thoroughly. The mixture is then pressed into tubes in the form of hydrodynamic pressing at a specific pressure of 4.5 t / cm. After that, the resulting product is dried in a drying cabinet at 150 ° C for 3 hours and sintering in argon at 1850 ° C for 2.5 hours with step heating and drying for 1 hour at 950 ° C. After cooling, the resulting product is impregnated with a mixture solutions of copper and chromium salts, taken in the following ratios x: 3.72 g of Cu (.NOj) 2 6H20, dissolved. in 398.6 g of water, and 0.878 g of Cg (C.N3O2 jH20, dissolved in 146.3 g of water, for 40 minutes. Then, the resulting product is dried at 120 ° C for 2 hours in a drying cabinet, calcined in a muffle ovens for 2 hours and reduced in a stream of hydrogen at 300 ° C for 60 minutes, the catalyst thus obtained has the composition, in percent by weight: Copper -, -0.4 Chromium oxide i .0.27 Ka |) bid silicon 88.6 Chrome. 0.5 Silicon. The rest of the ethanol in an amount of 100 ml is passed through a semi-catalytic catalyst with a bulk velocity of 5.2 hours. Heating of the catalyst in the reaction zone is carried out with a voltage of 8.5 V. The output of acetaldehyde is 65%. Selectivity is 100%. Example 3. To a mixture of powders containing, g: K-4-55 197.2 silicon carbide, metallic chromium 1.0, silicon 0.2, petroleum coke 2, a solution of bakelite in alcohol is added in an amount of 100 mp, mix the mixture thoroughly. The mixture is then pressed into tubes in the form of a mouthpiece pressing at a specific pressure of 5 tons / cm. After that, the resulting product is dried in a drying cabinet at 150 ° C for 3 hours and sintering in argon at 1850 ° C, for 2.5 hours with step heating and holding for 1 hour at 950 ° C. The cooled product is impregnated with a mixture of aqueous solutions of copper and chromium salts, taken in the following proportions: 4.65 g Cu (N0) 2 6 H20, dissolved in 491.83 g of water, and 0.975 g C (dissolved in 162.6 g of water, for 40 minutes Then the obtained product is dried for 3 hours in a drying cabinet, calcined in a muffle furnace at 500 ° C for 2 hours and reduced in a stream of hydrogen at 300 ° C for 40 minutes. The catalyst thus obtained has the composition , May.%: Copper .0.5 Oxide of chromium0.3 Silicon carbide 98.6 Chromium .0.5 Silicon. The remaining Ethyl Alcohol in the amount of 100 ml is skipped After the resulting catalyst with a space velocity of 5.5, produced by the applied voltage 9 V acetaldehyde yield was 85% selectivity} - 100%.

Claims (1)

(54 / CATALYST FOR DEHYDRATION OF ETHANOL, comprising a copper-containing component and chromium oxide, characterized in that, in order to increase the selectivity of the catalyst, it contains copper and additionally silicon carbide, chromium and silicon in the following components, wt. .%: Copper .0.3-0.5 Chromium oxide 0.24-0.3 Silicon carbide > 70-98.6 Chromium 0.5-1.0 Silicon Rest § £ = > 1 h at 950 ° C-,